A zone number needs a definition. A heart-rate estimate, a device’s configured range and a description of effort are not interchangeable measurements. Start by finding out what your guide means by the label.
Look for the method on the page or in the device instructions. Does it use a heart-rate estimate, device settings or a description of effort? If the author does not explain it, keep that definition marked as unknown.
02
Separate an estimate from a reading
An age-based estimate describes a population average. A displayed heart rate is a reading interpreted against a device’s zone settings. Making their numbers match would not establish your personal exercise threshold.
03
Use speech for the question it can answer
The talk test is a broad way to describe exercise intensity. It does not verify a precise Zone 2 boundary. You do not need to turn it into a pass-or-fail score.
FOLLOW THE INFORMATION3 different paths
An estimated range starts with assumptions.
01
InputAge, or the inputs a tool requests
02
MethodA stated formula and its assumptions
03
ResultAn estimated heart-rate range
Find the inputs and method before treating an estimate as a target.
Check next: Look for “method”, “formula” or “how this is calculated”. An undisclosed method stays unknown.